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Food desert or mirage?

Food security is an extremely important issue for the livability of cities. To educate citizens about it, accuracy in mapping is vital as well.

Upon first glance two weeks ago, I and a number of like-minded folks in the region sent along links and tweets to our contacts about "When Healthy Food is Out of Reach," a joint report from D.C. Hunger Solutions and Social Compact.

Sadly, it comes as no surprise that food deserts or or "grocery gaps," defined as an "area in the United States with limited access to affordable and nutritious food, particularly such an area composed of predominantly lower income neighborhoods and communities," exist in DC. Similarly, it comes as no surprise that, based on that definition, Wards 5, 6, 7, and 8 are the hardest hit.

However the maps used to convey the District's food deserts are misleading, particularly Maps 3 and 4 on pages 15 and 18 of the report. Below is an annotated version of Map 4, "Food Deserts in the District of Columbia."

Click to enlarge.

This illustrates what Mark Monmonier calls a "Blunder that Misleads" in his book How to Lie With Maps. According to the report, map 4 combines "census tracts where 51 percent or more of the population lives at incomes below 200 percent of the federal poverty level" and census tracts with "below-average access to full-service grocery stores."

The blunder—not a lie but rather a "cartographic fallibility"—comes from using census block group data. Entire block groups get designated as food deserts that either have no living residents (such as cemeteries and parks) and so do not have much income and require no access to food, or house institutions (like hospitals) and so do not have much income but likely provide food on site. Nearly 1/4 of the areas designated as food deserts may technically, but not realistically, fit the working definition.

Particularly during this time of increasing unemployment, homelessness, and hunger, advocacy groups across the District and the country are working overtime. Like many others, I want to help in the fight for social justice, but we need to be sure our data are airtight in order to effectively convey our messages.

Cross-posted at The District Curmudgeon.

Before moving to California, Jaime Fearer was a community planner in Greenbelt, MD, and she lived in Trinidad, DC, where she served on the neighborhood association痴 board. Jaime is now Planning & Policy Manager for California Walks


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From looking at the map above it is wrong.

If there are residences around all of those areas why aren't they on the map

For example Ft. Dupont Park there are residences on all sizes of the park but they arent represented as is the case with the area around Mt Olivet Cemetery/the Arboretum

By the way the map is wrong for the area by The Soldiers Home and the Cemetery nearby there is a set of apartments between the Home and the Cemetery so they would not be one continuous area

by kk on Mar 30, 2010 2:24 pm • linkreport

Another problem with these D.C.-only maps is that they do not take into account easily accessible facilities located right over the border in Maryland. In wards 7 and 8, specifically, two Safeways, two Shoppers Food Warehouses, and two Giants all directly over the D.C. border in P.G. County.

by Adam L on Mar 30, 2010 2:29 pm • linkreport

Another problem with the report is that they don't count Yes Organic Markets as grocery stores--although they do count Murry's.

It does look like they aren't making as good use of available GIS data as could be useful.

by thm on Mar 30, 2010 2:34 pm • linkreport

@ Adam L

Another good thing to have on a map like this would be

Just because something is across the ward doesn't make it easy to access.

Take where Central Ave & East Capitol meet in Maryland what buses go there 7 days a week and how often they run per day.

Hours of the store some stores close early not all Safeways, Shoppers, Giants operate the same hours.

the amount of car ownership in the ward

the amount of people in the ward that are transit dependent

the amount of bus/train routes that go pass where the store is.

by kk on Mar 30, 2010 2:41 pm • linkreport

First issue I see is a mix-up of census geographies - the quote pulled from the report references "census tracts", but the map shows block groups - which is it? Block groups are contained within census tracts.

It would have helped if the authors had created a food desert index applied to rank every block group, rather than a binary y/n equation. The index could have been normalized by the actual population count, which would have helped to reveal some of the inconsistencies noted in the posting.

by irate_reader on Mar 30, 2010 3:01 pm • linkreport

Murry's sells food?

by andrew on Mar 30, 2010 3:30 pm • linkreport

Good work Jaime. It's good to see you back on the site.

I also read "How to Lie With Maps." Quite an informative and interesting book. Everyone who makes maps (and diagrams) should take a look at that book.

by Matt Johnson on Mar 30, 2010 3:51 pm • linkreport

Should be easily possible for someone to take the data in question and factor out the institutional areas (i.e. parks, government land, etc etc) to provide a more accurate map...

by Froggie on Mar 30, 2010 5:03 pm • linkreport

Yikes. Good catch.

From the report, it looks like the DC Office of Planning created that particular map. All of the others were created by Social Compact. The others do, by the way, include full-service grocers across the jurisdictional boundaries.

by Daniel on Mar 30, 2010 5:30 pm • linkreport

Another faux pas: immediately next to the Soldier's Home is Catholic University and a mish-mash of other Catholic institutions in which few if any people live and are not otherwise provided with food.

by Dave Murphy on Mar 30, 2010 6:41 pm • linkreport

@Dave Murphy - We thought about including the universities highlighted in purple here (CUA and the smaller institutions you mentioned, along with Gallaudet), but then decided against it. But student income - or lack thereof - is often quite different than the type of poverty i believe the study is trying to highlight (and i say this as a poor, non-traditional student).

Incidentally, the section that contains Gallaudet also contains the Florida Ave./Union Market, where there is tons of food.

by jaime on Mar 30, 2010 6:50 pm • linkreport

Also, there's a big blotch in SE over Nationals Park and the Navy Yard (although there are residences north of M Street.

by Just161 on Mar 30, 2010 7:20 pm • linkreport

i think a post like this -- and, really, any and every post -- should try to get a comment/response from the parties responsible for producing the reports you're critiquing -- just makes things more interesting, seems more fair, probably makes for a better article, etc. not saying that's possible -- just saying that's desirable.

but we need to be sure our data are airtight in order to effectively convey our messages

i don't think so.

of course, airtight is often the best option, but really, all we need is 'good enough' data/reports to make our case. this is not global warming -- there's no high-powered international consortium of oil companies trying to derail pro-human legislation on the world stage.

'good enough' works as long as the running popular notion is already thought to be true, and/or as long as nobody has a profound interest in seeing to it that poor people don't have access to healthy food.

'good enough' recognizes that there is real harm being done while we futz around and maintain the status quo.

so, just crank out solid if imperct report, and if it agrees with what you believe or want to sell, then you go to the city council and say, 'See?' -- then they have the political cover they need to act.

on one end of the extreme in the wrong direction, take the case of San Francisco -- we took 3+ years to do an EIR (environmental impact review) to tell us that new bike lanes would not destroy the earth. all the while, SF had no new bike infrastructure, not even bike racks, for 3+ years. i'd have been OK with a report generated in a couple of months that said, "eh - it looks good, Charlie."

once it comes to implementation, then yes - we'll probably want the most accurate data/analysis available, and by then, we can be reasonably sure that businesses won't want to locate next to graveyards, even if they have subsidies from programs like Pennsylvania's FFFI.

by Peter Smith on Mar 31, 2010 1:33 am • linkreport

I have made the same points as Adam L and thm over the years, although there are food stores across the border in Montgomery County too, or in PG County abutting Ward 5 (I can think of 6-7 if you count the Save-a-lot on Sargeant Road). Plus, I don't think they count the PanAm markets.

It's like with bike planning, it isn't just building the facilities, it's also the parallel programming and support to get people to bike.

With food issues, there are two dimensions: access and food security; and what people eat. (From 1987-1991 I worked for the nation's leading nutrition advocacy group.)

Although there is seeming lack of access, there are grocery stores pretty close to the "desert" areas, they just aren't in DC. Furthermore, people usually have access to others with cars, etc., to be able to get to the store, plus there is transit.

The other issue is whether or not people eat healthily (fruits and vegetables, fresh or frozen or canned, legumes, limited high fat foods such as meats). That's another issue.

My ex-wife worked at the Food Research and Action Center when I worked at CSPI. The difference between the food at our respective parties was stark -- we had veggies and low fat dips, etc., they had junk food. I used to joke that they just cared about whether or not people ate, while we cared about the nutritional quality of what people ate.

by Richard Layman on Mar 31, 2010 10:28 am • linkreport

This is a good example of where a strictly quantitative approach is misleading, esp. if people don't take into account boundaries, distortions like parks, etc. There probably is less availability of fresh food in some of the desert areas and the marketing of the stores probably contributes to this, even within chains. There are cities like Atlanta that are much more desert-like. Few chain stores and independents that mostly sell junk food, lottery tickets and alcoholic beverages. The "fresh" food (including its frozen counterparts) in those places is usually something to avoid.

One problem with DC has been the obvious monopolies that have been allowed to form. For many years, Safeway had the vast majority of DC stores and almost all the ones E of the Park. Giant closed stores, but rarely opened new ones during this period (70s-00s), and the other stores tended to be small. Giant charged the same prices as in the suburbs, but others did not. Now, I wonder if Safeway seems to be closing stores where Giant has established large, modern locations, like Rhode Island Avenue (they closed another RI Ave store a few years ago). I was surprised they didn't close the Columbia Road store. I wonder what kind of chain stewardship we'll see in the future.

by Rich on Mar 31, 2010 11:06 am • linkreport

@ Rich

Giant & Safeway always do the one store close the other opens.

There was a Giant & Safeway on/off Minnesota Ave the Safeway is still there the Giant closed and Charter Health is in its former location.

Giant & Safeway off of Good Hope RD/Alabama Ave/25th Street SE.

The Giant was doing fine then Safeway built a new store across the street which inturn made Giant do worst then they closed the store and Murrys moved in. Then like 10 years later Giant built a new store further down on Alabama Ave.

Samething with Rhode Island Ave

Its just a cycle that does back and forth. Those two stores have had basically a Duopoly on DC for 2-3 decades

by kk on Mar 31, 2010 1:56 pm • linkreport

Hello Jaime,

Iテや冦 the geographer who created the map graphic (Map 4) as a courtesy to DC Hunger Solutions. The テや炉ood Desertテや data are a product of Social Compact/ DC Hunger Solutions.

I was asked to produce a map showing areas where テや炉ood Desertsテや and high poverty overlap. To make this overlap more visibly apparent, I removed all parks from the map. This was my mistake. In doing this, the map I created inaccurately reveals three "Food Desert" areas that were originally meant to be obscured by the parks (reference Map 3). A revised version of this map will provide an overlay of parks and zero population census block group geographies. (a draft has already sent to both DC Hunger Solutions and Social Compact)

You (and others who have commented) make some excellent points that dig deeply into issues of accessibility. How can we properly analyze and display テや和ccessテや at such a coarse scale? What data are most appropriate given the inherent drawbacks of using 2000 Census geographies? How do we define テや廩ealthy Food Accessテや? I agree wholeheartedly with your premise that census geographies arenテや冲 an optimal means of deriving テや彗ccessテや. We at the Office of Planning have been looking carefully at notions of accessibility for some time now:

In performing an analysis of the entire District of Columbia, I donテや冲 think using census block groups is completely inappropriate, given the scale. If the report discovers verifiable spatial patterns at a coarse scale, even if the finer scale geographic truths are not evident (e.g. all the population in St. Elizabeths is shifted to East Campus), the findings are no less valuable.

Jaime, thank you for bringing this matter to our attention. The spirited dialog it has generated proves that healthy food access is an issue of great importance to our constituents. Please feel free to contact me directly regarding this map.

Best regards,

J. Graham
DC Office of Planning

by J. Graham on Apr 1, 2010 4:59 pm • linkreport

email at:

by J. Graham on Apr 1, 2010 5:02 pm • linkreport

I'd like to thank J. Graham for his thoughtful response above. Additionally, we've posted a detailed response from Social Compact's Carolina Valenica at The District Curmudgeon.

by jaime on Apr 2, 2010 5:13 pm • linkreport

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